• 제목/요약/키워드: 4A

검색결과 303,708건 처리시간 0.163초

Catechin 이합체 (Catechin Dimer)

  • 안병준
    • 생약학회지
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    • 제10권2호
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    • pp.41-53
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    • 1979
  • A 6', 8a-bonded catechin dimer was synthesized by action of phenoloxidase on 2mol (+)-catechins. The same dimer and other two dimers which are also 6', 8a-bonded were isolated from the fresh cortex of Quercus robur. The 4, 8a-bonded and the etherified 4, 8a-bonded dimers were isolated from it. It was discussed about the meaning of the enzymatically produced 6', 8a-bonded dimers in plant cell. The isolated dimers are as following: 1. 6', 8a-bonded dimers: (+)-catechin-(+)-catechin-6', 8a-dimer(IX), (+)-catechin-(+)-gallocatechin-6', 8a-dimar (XIII), (+)-gallocatechin-(+)-catechin-6', 8a-dimer(XIV). 2. 4, 8a-bonded dimers: (+)-catechin-(+)-catechin-4, 8a-dimer(X), (-)-epicatechin-(+)-catechin-4, 8a-dimer (XI), (+) -galloatechin-(+)-catechin-4, 8a-dimer (XII). 3. 4,8a-bonded dimers with ether linkage: etherified(+)-catechin-(+)-catechin-4, 8a-dimer (XV), etherifid (+)-catechin-(+)-gallocatechin-4, 8a-dimer (XVI), etherified (+)-gallocatechin-(+)-catechin-4, 6a-dimer (XVII).

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One-step Synthesis of Supramolecular Rectangles Starting from ($\eta^5$-Pentamethylcyclopentadienyl)rhodium(III) Aqua Complex

  • 한원석;이순원
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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    • pp.27-27
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    • 2002
  • [Cp*Rh(H₂O)₃](OTf)₂ (1) reacts with a stoichiometric amount of A and B [ A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)] in acetone at room temperature for 3 h to give the supramolecular complexes [Cp*₄Rh₄(μ-A)₄(μ-B)₂] [A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)]. Complexes 2a and 2b have been structurally characterized by X-ray diffraction.

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IN2001 Regulates CYP3A4 Gene Expression in Hep G2 Cells

  • Ahn, Mee-Ryung;Kim, Dae-Kee;Sheen, Yhun-Yhong
    • 한국환경성돌연변이발암원학회지
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    • 제24권4호
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    • pp.171-179
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    • 2004
  • Cytochrome P4503A4(CYP3A4) is the most abundnat CYPs in human liver, comparising approximately 30% of the total liver CYPs contents ans is involbed in the metabolism of more than 60% of currently used therapeutic drugs. The expression of CYP3A4 is induced by a variety of structurally unrelated xonobiotics including the antibiotic rifampicin and endogenous hormones, and might be mediated through steroid and xenobiotic receptor(SXR) system. The molecular mechanisms underlying regulation of CYP3A4 gene expression hae not been understood. In order to gain the insight of the molecular mechanism of CYP3A4 gene expression, study has been undertaken to investigate if the histone deacelylation is involved in the regulation of CYP3A4 gene expression by proximal promoter or not. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. HepG2 or Hena-I cells were transfected with a plasmid containing~1kb of the CYP3A4 proximal promoter region (-863 to +64bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR or hER. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, or with estradiol, in order to exmine to regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In HepG2 cells, CYP3A4 inducers and estradiol increased significantly the luciferase activity by CYP3A4 proximal promoter, only when TSA was co-treated after SXR cotransfection. In the case of Hepa-I cells CYP3A4 inducers and estradiol incressed modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection in contrast to HepG2 cells. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Futher a trans-activation by SXR may demand other species-specific transcription factors.

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Dioxygen Transfer from 4a-Hydroperoxyflavin Anion to Isomeric Aminophenolates

  • Sam-Rok Keum;Ki-Bong Lee;Thomas C. Bruice
    • Bulletin of the Korean Chemical Society
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    • 제11권2호
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    • pp.95-99
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    • 1990
  • The dioxygen transfer reaction from $N^5$-ethyl-4a-hydroperoxy-3-methyllumiflavin anion (4a-FlEtOO-) has been extended to isomeric aminophenol systems (1a-4a). O-aminophenol (o-AP, 1a & 2a) and p-aminophenol(p-AP, 3a & 4a) were turned out to be good substrates, whereas m-aminophenol(m-AP, 5a) was not. This is due to the charge location which is not on the carbon bearing the amino group. o-AO's react with 4a-FlEtOO- to give isophenoxazine derivatives (6 & 7) and with p-AP's to produce p-benzoquinone derivatives (8 & 9). The partition coefficients $(k_2/k_3)$ of 1a & 2a were $4.84{\times}10^{-4}\;&\;1.66{\times}10^{-5}M$, respectively and those of methylated aminophenolates, 2a & 4a were 4-10 times greater than nonmethylated substrates, 1a & 3a.

감정단어 발화 시 억양 패턴을 반영한 멜로디 특성 (Tonal Characteristics Based on Intonation Pattern of the Korean Emotion Words)

  • 이수연;오재혁;정현주
    • 인간행동과 음악연구
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    • 제13권2호
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    • pp.67-83
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    • 2016
  • 본 연구는 감정단어의 억양 패턴을 음향학적으로 분석하여 멜로디의 음높이 패턴으로 전환한 뒤 그 특성을 알아보았다. 이를 위해 만 19-23세 여성 30명을 대상으로 기쁨, 화남, 슬픔을 표현하는 4음절 감정단어의 음성자료를 수집하였다. 총 180개의 어휘를 수집하고 Praat 프로그램을 이용하여 음절 당 평균 주파수(f0)를 측정한 후 평균 음정과 음높이 패턴의 멜로디 요소로 전환하였다. 연구 결과, 첫째, 감정단어의 음높이 패턴은 '즐거워서' A3-A3-G3-G3, '즐거워요' G4-G4-F4-F4, '행복해서' C4-D4-B3-A3, '행복해요' D4-D4-A3-G3, '억울해서' G3-A3-G3-G3, '억울해요' G3-G3-G3-A3, F3-G3-E3-D3, '불안해서' A3-A3-G3-A3, '불안해요' A3-G3-F3-F3, '침울해서' C4-C4-A3-G3, '침울해요' A3-A3-F3-F3으로 나타났다. 둘째, 음 진행에서는 기쁨이 넓은 간격의 도약 진행, 화남이 좁은 간격의 도약 진행, 슬픔이 넓은 간격의 순차 진행 특성을 보였다. 본 연구에서는 감정의 속성과 본질, 한국어의 음성 특성을 고려하여 감정단어의 억양 패턴을 분석하고, 이를 멜로디 요소에 반영한 특성을 제시하였다. 또한, 체계적이고 객관화된 방법으로 말과 멜로디의 전환 가능성 및 적합성을 확인한 것에 의의가 있다. 본 연구의 결과는 감정을 효과적으로 표현할 수 있는 멜로디 창작 방안을 마련하기 위한 근거 자료로 활용될 수 있다.

Pseudogobio esocinus (Cypriniformes) 젖산수소이탈효소 동질사량체들의 정제, 역학 및 면역화학 (Purification, Kinetics and Immunochemistry of Two Homotetrameric Lactate Dehydrogenase Isozymes in Pseudogobio esocinlus (Cypriniformes))

  • 김명옥;염정주
    • 한국동물학회지
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    • 제32권4호
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    • pp.420-428
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    • 1989
  • Pseudogobio esocinus의 심장, 신장 및 간 조직은 하부단위체 C를 함유하는 젖산수소이탈효소를 갖고 있음이 확인되었다. 하부단위체 A 및 B에 대한 유전자들의 조직 발현은 다른 포유동물의 것과 유사하였으며 분자량은 140,000 정도로 추정되었다. Oxamate gel을 사용한 chromatography결과 A4 동위효소는 NAD+보다는 column buffer에 의해 용출되었다. B4 동위효소는 CM-Sepharose column을 사용하여 부붙 정제되었다. B4 동위효소는 물론 A4 동위효소도 고농도의 Pyruvate에 의해 저해되었다. A4 동위효소의 affinity chromatography 상 행동과 Pyruvate 저해 정도로 보아 A4 등위효소는 B4 동위효소 두 역학적으로 유사하다고 사료된다. P. esainus A4 동위효소에 대한 항체는 mouse A4 등위효소와 반응하지만 동종의 B4 동위 효소와는 반응하지 않는 특성으로 보아 하부단위체 B는 진화과정에서 보존성이 낮은 것으로 사료된다. Three tissues of heart, kidney and liver of a primitive cvprinid Pseudogobio esocinus were found to have lactate dehydrogenase isozyme(5) containing subunit C. Tissue expressions of genes for subunits A and B were similar to those of mammalian species. Molecular weight of the isozymes were estimated to be 140,000 approximately. Affinity chromatography of the isozymes on the immobilized oxamate gel revealed that A4 isozyme was not elected in NAD+ but in column buffer. B4 isozune was isozpnatically purified by subjecting kidney extract to a CM-Sepharose column. Ae isozvme as well as B4 isozvme was inhibited by high concentrations of pyruvate. The affinity chromatographic behavior and susceptibility to pyruvate inhibition of the A4 isorpne suggest that A4 isozwne is similar to B4 isozyme kinetically. Antibodies against p. esocinus A4 isogyme reacted with mouse At isozyme but not with p. esocinus B4 isogyme, reflecting that subunit B is less conservative in its evolution.

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e-4WD 시스템 개발 (Development of electric Four Wheel Drive System)

  • 조희영
    • 드라이브 ㆍ 컨트롤
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    • 제13권1호
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    • pp.10-17
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    • 2016
  • e-4WD(Electric-4WD) system is a 4WD(4-Wheel Drive) System that can transform a car into a Hybrid System. e-4WD consists of a Motor, Inverter, Speed reducer and Clutch. The Motor, Speed reducer and Clutch are installed on the rear sub-frame as a chassis module type. The inverter is installed separately. Compared to a mechanical 4WD, the e-4WD system has many advantages. For example, the reduced number of drivetrain components makes better use of the space. Driving with a motor only at low speed improves fuel economy and reduces exhaust gas. Engine downsizing is available because the motor assists the engine. The performance of a conventional HEV(Hybrid Electric Vehicle) system can also be maintained. This paper proposes the specifications of components and the control logic for an e-4WD System. And the effect of the e-4WD system is proven using a test vehicle equipped with components under various test conditions.

Lactobacillus acidophilus GP4A 박테리오신의 정제, Bacteriolytic 작용 및 생산 관련 Plasmid의 선별 (Purification, Bacteriolytic Action and Plasmid Isolation of Acidocin 4A Produced by Lactobacillus acidophilus GP4A)

  • 한경식;전우민;김영훈;김세헌
    • Journal of Dairy Science and Biotechnology
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    • 제21권2호
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    • pp.114-119
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    • 2003
  • Lactobacillus acidophilus CP4A 균주가 생산하는 acidocin 4A를 정제하고자 ammonium sulphate 침전법 , Octyl-sepharose CL-4B column chromatography, $C_{18}$ Sep-Pak cartridge, $C_{18}$ RP HPLC, HPLC gel filtration을 실시하였고 tricine SDS-PAGE를 통해 약 4.1 kDa의 박테리오신임을 확인하였다. Acidocin 4A의 항균작용 기작을 L. delbrueckii subsp. lactis ATCC 4797을 대상으로 TEM을 이용해 관찰한 결과 세포벽이 해리되고 세포벽사이로 세포내용물이 용출되어 궁극적으로 cell lysis가 일어나는 bacteriolytic 현상을 확인하였다. 또한, acidocin 4A의 생산에 관련된 유전자의 존재 위치를 파악하고자 EtBr을 이용한 curing방법을 실시하였으며 그 결과 약 20 kb 크기의 plasmid에 acidocin 4A 생산과 자체 면역에 관련된 유전자가 존재함을 알 수 있었다.

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파킨슨병 동물 모델에서 도파민세포의 감소와 관련된 Slc6a4 발현의 증가 (Increased Slc6a4 Expression Associated with Decreased Dopaminergic Neurons in an MPTP Induced Parkinsonism Mouse Model)

  • 여수정
    • Korean Journal of Acupuncture
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    • 제38권3호
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    • pp.133-139
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    • 2021
  • Objectives : Parkinson's disease is a neurodegenerative disease caused by a decrease in the dopaminergic neurons in the substantia nigra. The abnormal expression of solute carrier family 6 member 4 (Slc6a4) has been reported in patients with Parkinson's disease. Methods : In this study, we used MPTP to examine the changes in the expression of Slc6a4 in the brain of mice with Parkinson's disease and investigate its effect on dopaminergic neuronal cell death. Results : In the examination of the Slc6a4 expression in the substantia nigra of MPTP-treated mice for 4 weeks. The gene expression was increased compared to the normal group. To investigate the relationship between Slc6a4 and dopaminergic neurons, we performed a study using siRNA of Slc6a4 in the dopaminergic neuronal cell line SH-SY5Y. Using the siRNA of Slc6a4 to evaluate gene expression, it revealed that the tyrosine hydroxylase (TH) expression increases when Slc6a4 decreases. Moreover, this confirms its effects on the dopaminergic neurons. Additionally, through the evaluation of factors related to apoptosis, in particular, it was established that the value of bax/bcl2 decreased and was affected. These results suggest that a decreased Slc6a4 expression induces an increase in TH expression, providing a mechanism of action for dopaminergic neurons regulated by Slc6a4 expression. Conclusions : Slc6a4 is deemed to be involved in the regulation of dopaminergic neurons, suggesting that an increased Slc6a4 expression induced by MPTP may influence a reduction of dopaminergic neurons.

Diagnostic Utility of p63 (Ab-1) and (Ab-4) Tumor Markers in the Squamous Cell Carcinomas of Head and Neck

  • Khan, Nauman Rauf;Khan, Amna Nauman;Bashir, Saira;Khan, Ayyaz Ali;Suleman, Bilquis A.;Chaudhry, Saima
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.975-978
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    • 2012
  • P63 is a gene product required in cell cycle regulation which plays vital roles in tumor differentiation. Aims of the present study were to assess the frequency, pattern, sensitivity and specificity of two p63 protein clones P63 4A4 and P63 4A4+Y4A3 in squamous cell carcinomas (SCCs). Thirty cases of head and neck region SCC diagnosed on the basis of H&E staining were examined along with 60 cases of head and neck region biopsies other than squamous cell carcinoma, negative on H&E staining, were taken as control. Immunostaining was performed on slides according to the Thermo Scientific UltraVision LP detection System. P63 4A4+Y4A3 clone is more sensitive 96.6% in comparison to 86% in P63 4A4 with having greater NPV of 98.3%. The results signify the importance of P63 4A4+Y4A3 marker over the old markers and may be used as a confirmatory marker of squamous cell carcinoma.